Researchers from ETH Zurich and Total (French oil and gas company) have synthesized a new catalyst that can convert hydrogen and CO2 into methanol. This process, which can offer achievable market potential, opens new doors for the sustainable generation of chemicals and fuels.
Yet, the world economy depends on the fossil carbon sources of natural gas, petroleum, and coal, both to produce fuel and as a raw material used by the chemical industry to produce plastics and numerous other chemical compounds.
Despite the fact that attempts have been previously made to discover methods to produce chemical products and liquid fuels from alternative, sustainable resources, these have not yet developed beyond niche applications.
At present, researchers from ETH Zurich in collaboration with Total have developed a new mechanism that can efficiently convert hydrogen and CO2 directly into methanol. Methanol is considered as a bulk chemical or commodity that can be easily converted into fuels and a range of chemical products, including those that are at present chiefly based on fossil resources. In addition, methanol itself could be used as a propellant, for instance, in methanol fuel cells.
An indium oxide-based chemical catalyst developed by Javier Pérez-Ramírez, Professor of Catalysis Engineering at ETH Zurich, and his team is the main product of the new process. Recently, the researchers have been able to show in their experiments that indium oxide could catalyze the essential chemical reaction.
Also at that time, it promisingly resulted in the production of only methanol and nearly no by-products except water. The catalyst was also found to be very stable. Indium oxide, however, was not active enough to serve as a catalyst; the requirement of a large amount of indium oxide prevented it from being a commercially feasible option.
The researchers have successfully achieved a significant increase in the catalytic activity of indium oxide, without affecting its stability or selectivity, by treating it with a small amount of palladium.
“More specifically, we insert some single palladium atoms into the crystal lattice structure of the indium oxide, which anchor further palladium atoms to its surface, generating tiny clusters that are essential for the remarkable performance,” stated Cecilia Mondelli, a lecturer in Pérez-Ramírez’s team.
Pérez-Ramírez indicated that with the help of modern analytical and theoretical methods, catalysis can currently be considered nanotechnology, and actually, it becomes apparent from the study.
The Closed Carbon Cycle
Nowadays, deriving methanol on an industrial scale is done exclusively from fossil fuels, with a correspondingly high carbon footprint. Our technology uses CO2 to produce methanol.
Pérez-Ramírez, Professor of Catalysis Engineering, ETH Zurich
This CO2 could be obtained either from the atmosphere or—more simply and efficiently—from the exhaust emitted by combustion power plants. Even if fuels are prepared from the methanol and then combusted, the CO2 is recycled and hence the carbon cycle is completed.
Electricity is required to produce hydrogen, which is the second raw material. The researchers, however, indicated that if this electricity could be obtained from renewable sources such as solar, wind, or hydropower energy, it could be used to produce sustainable methanol and thus sustainable fuels and chemicals.
Pérez-Ramírez added that in comparison with other existing methods that are used to generate green fuels, this method is more advantageous as it is almost ready for the market. ETH Zurich together with Total has filed a patent for the technology. Currently, Total has planned to develop the method and successfully apply it in a demonstration unit over the next few years.